I really can't see using a full suspension bike for serious touring. Pedaling eficiency (especially up hills), weight and, if this is a long tour, moving parts to worry about repairing, are all serious issues. For a short (2-6 day) supported tour or a short tour with a trailer, it could be doable, but not the most pleasant choice.
Another factor is cost. Others may know better, but I don't know of any decent full suspension bike for under a grand, and I'd be leary about a used suspension. A good quality old school steel mountain bike, cyclocross bike or even a true tourer can be found used for a a few hundred.
Any suggestions for "touring worthy" full suspension bikes? I realize they are less than efficent, but they are so comfortable.
Comfort is important, so I understand your question. Have you actually tried a *real* touring bicycle with good tires and a good saddle? There are many people like yourselves who prize comfort above all and would consider their non-suspended touring bicycle very comfortable. A sprung saddle or suspension seatpost, and a wider tire would soak the road vibration and bumps very well and all of them have advantages over a full suspension mountain bike, which is designed for different riding conditions and priorities.
Look at the touring bike picture thread and you will see what people will do for comfort.
In the last year or so suspension with lock-out ability has become common and available on the mid price point. Lock out allows the suspension to become stiff enough to prevent energy sapping bobbing when on the road. However as other have said, weight penalties must be paid.
My Rhino, with it's cyclo-cross setup, could be used as a full suspension tourer if I fitted Marathon tires and a rear rack. I prefer to keep it as a stripped down for dedicated off-road use, and use a lighter regular sized touring bike for road use.
There are certainly people doing it on the great divide type tours. Full suspension is not a good deal on road surfaces the kinds of jolts on normally encounters are more like vibrations, and the long travel mountain bike shocks do not deal with them all that well. I have a recumbent touring bike with suspension, the suspension part works well.